Automatic control of exhaust gases for mixture heating



D. FIRTH April 11, 1933.

AUTOMATIC CONTROL OF EXHAUST GASES FOR MIXTURE HEATING Filed April 6, 1931 2 Sheets-Sheet l /.l" [YE-l Dazu April 11, 1933. D. FIRTH 1,903,446

AUTOMATIC CONTROL OF EXHAUST'GASES FOR MIXTURE HEATING L Filed April 6, 1931 2 Sheets-Sheet 2 II/I IIIII I 9/J l (////"""L I Z Vide an improve ama- A r. 11, 1.933 I U ITED STATES PATENT caries n 0] FLINT, MICHIGAN, A. CORPORATION OF ILLINOIS auron'rrc cannot or 'nmusr eases r03 mrm name 7 Application fled April 1831. Serial No. 528,217.

This invention relates to an improved heat control for the induction system of internal combustion en es.

It is a principal object of this inventlon to provide an improved and simplified heat control system adapted to automatically compensate forvarying conditions of operation and engine temperature. In a carbureter type of engine operating under widely varying conditions of speed and load as well as temperature, as in automotive service for example, the maximum power output is obtainable when the engine is supplied with a cool incomin fuel and air mixture, since the cooler the mlxture -the greater the weight of unit charges sup lied to the engine cylinders.

It is another 0 iect of this invention to proheat control s stem for internal combustion engines whereln a throttle control varies the heat supplied in accordance with load conditions to provide the maximum heat under idling conditions, and wherein this control is modified by a the'rmostaticcontrol the responsiveness of which is balanced between radiation or hood temperatures and conductivity from the heated manifold, the balance being predetermined to limit the efiectiveness of the heat conducted to the thermostat. By controlling the effect of conductivity the operation of the heat control system is improved, since whens-operating a vehicle at igh road speeds the increased air flow through the radiator decreases the hood temperature below that occurring at lower speeds, so that if the thermostat responded .to radiation only it would allow more heat to be supplied to the induction system, aresult 0 pcsite to that required under the specifi opcrating conditions. By arranging for a redetermined conductivity eifect on the t ermostat, the greater volume of exhaust gas flow at high speeds will result in increased conductivity to offset the drop in hood temperatures, so that by a proper control of conductivity the desired operating conditions can be maintained. A further advantage of the combination of radiation. and a limited conductivity energiZat-ion of the-thermostat results when decelerating since during a period and simplified automatic of high speed operation a considerable amount of eat is stored up in the metal of the induction s stem, so that when the vehicle is slowed own there is enough residual heat for satisfactory engine operation and the responsiveness of the thermostat to conducted heat causes an expansion thereof which cuts off additional heat supply to the induction system. q

Other and further important objects of this invention will be ap arent from the disclosures in the specification and the accompanyin drawings. I

' his invention in a preferred form) is illustrated in the rawings and hereinafter more fully described.

On the drawin I Figure 1 is a iagmentary side elevation of an engine cylinde 1 block to which a mani-" folding s stem embo ilying this invention has been app 'ed.

Fi re 2 is an enlarged section on the line II I of Figure 1 to show the position of the thermostatic control relative to the jack eted induction manifold riser.

Figures 3, stand 5 are fragmentary sections on the line III-III of Figure 2.

DAVID FIRTH, OI FLINT, MICHIGAN, ASSIGNOB TO mm OABBUBETEB comm, I

Figure 3 illustrates the heat on position of the thermostatically operated valve for cold en ine conditions.

. igure 4 shows the heat control valve in a mi position corresponding to a normal operating temperature Figure 5 shows the control valve in the extreme cool position for shutting oif the supply of heat to the jacketed manifold;

As shown on the drawings:

An internal combustion engine cylinder block is indicated by the reference numeral 10 in- Figure 1, an exhaust manifold 11 being applied to exhaust orts in the side thereof in the usual manner. imilarly, an intake'manifold 12 is applied to intake ports, alternating in position with the exhaust ports, and this intake manifold is fed by a central riser having a heating jacket 13 therearound. As shown in the section of Figure 2 the riser come prises twin passages 14; which are fed by a duplex car ureter 15. The duplex. form of manifold is of advantage for multiple cylin- 'ders to prevent a surging flow in'the horizom Ital manifold 12 but forms no part of, the

present invention. 1 1

A duplextype of throttlevalvelG is positioned in each passage 14 of the riser, the two throttle valves being mounted on a common I shaft 17 externally operable by a throttle lever 18 including an idling adjustment arm 1.9 and a heat control lever arm 20 which is con- 19 nected by a rod 21 to a lever 22 operatin a main heat diversion valve 23 shown dotte in Figure 1 asmounted in an exhaust diversion valve body 24. Thevalve23 serves when in the position shown to divert exhaust gases from the exhaust manifold 11 to a pi e 25 leading to the riser heating jacket 13 rom which the gases return to the exhaust diversion valve body, below the valve therein, through an outer pipe 26 enveloping the supply fpipe '25. This arrangement is a vantageous r appearance standpoint and because the supply of exhaust gases is protected from undue cooling by the returning ases.

The above described manifol heating sys tern .could'be designed for satisfactory operation at a predetermined uniform operating temperature, since the throttle control of the diversion valve 23 would result in the maximum diversion of exhaust gases under idlin conditions, with mdecreasing diversion o exhaust gases to the heating jacket as the throttle was 0 ened, until the diversion valve became turns to a substantially vertical posh tion, under which conditions the exhaust gases would have an unobstructed passage straight through the diversion valve body so that sub-v stantiall no heat would be supplied to the manifol heating jacket, a result highly desirable for the production of maximum power in the upper range of throttle openings. However t e fore oing arrangement would be lacking in fiexi ility to meet warming up conditions, or to operate satisfactorily under temperature conditions other than hermales for example under varying climatic conditions. To provide pro er flexibility to meet varying operating con itions I rovide a thermostatically controlled valve 2 in the connections between the exhaust diversion valve and the manifold heating jacket, which valve is so arranged that it can b ass all or part of the exhaust gas flow mm the.

suppl i 25 to the return pipe 26, thus reducing t e flow of. exhaust gases through the manifold heating jacket I have found that it is desirable to have the thermostatic control chiefly responsive to air or'hood temperatures, but balanced by a limited response toconducted heat from the metal of the heating jacket or manifold, because of the residual heat stored up therein under operating conditions'.

The valve 27 is mounted on a cross shaft 28 in a side housing 29 on the riser jacket, the- 6 housing being arranged to receive theends om an of the pi cs 25 and 26 and having a partition 30, of w ich the valve forms a continuation when the valve is in its horizontal position. The partition 30 is continued to the center line of the riser jacket and preferably is so arranged that the exhaust gas "supply, pipe 25 discharges below the partition so that t e hottest gases'first circulate around the throttle location and then rise over the partition, 30 to return over valve 27 to the outer return" 76 pipe 26. One method of operating the valve 27 is to provide gear teeth 31 on the shaft 28 thereof operable by a reciprocating piston 32 having rack teeth formed by a worm-like thread cut 89 thereon, which iston isconnected to a thermostat comprising an expansible corrugated sealed cylinder 33 containing an expansible or volatile fluid which expands or "vaporizes in a predetermined manner in response to f 35 temperature increases. Such thermostats per se are well known and can be selected to'hav'e a predetermined rate of-movement in" the de sired range of temperature controlQ The thermostatic cylinder 33 is preferably mounted in a protective housing 34 separate from I the manifolding system of the engine in order that the surrounding air temperature may have the maximum efiect thereon. -Under" such circumstances, if conductivity of the necessary mounting be temporarily neglected, the thermostatic control will be responsive to the surrounding air temperatures lll the case of an automotive vehicle of the hood tempera tures which are normally higher "than" free atmospheric temperatures due to the heat of the engine and the prior heatin' efi'ect of the usual radiator on the air ow; the'r'ethrough.

In order to control the co'nductivity'of the W5 thermostatic mounting to give the desired bah ancing effect of themanifold temperatures on the thermostat, I have found it desirable to partially insulate the thermostat mounting from the manifold heating jacket) To this end the valve shaft 28 is mounted atthe ear end thereof in a mounting collar 35"havj mg a pocket 36 therein covered by a pair'cf insulating washers 37 which form an insulat ing air space. The collar is further insulated i from the housing 29 by gaskets 38. The 'col'' lar 35 is formed with an elbow""39 suitably journalled for the valve shaft 28 and the ther mostat piston 32 and the elbow carries'a' mounting fiange 40 to receive thetherim'istatf" cover.34. The flange 40 is providedjwith a' asket 41- and is also erforated asat .42'to further reduce the con uctivityof the mount-{ ing. The resulting reduced heat conductivity of the mounting has been found to properly balance the direct or'air temperature res onsiveness of the thermostat to accomplis j au improved combmed control which" difieren tiates between variations in engine operating temperatures due to varying air temperatures a and loads.-

and those due to varying operating speeds In the operation of the heat control of this invention the interconnectedthrottle and diversion valve serves to supply maximum heat under idling conditions and minimumheat under the higher range of throttle operation. This is desirable since the engine requirements are affected by the load and also because a much greater volume of exhaust gases is available under conditions of wide throttle "openings when such volume isleast required 'for heating purposes. The thermostaticcontrol further modifies the heat supply to the induction system in accordance with air and manifold temperatures. In starting up a cold engine or under cool air conditions the thermostat is contracted and holds the valve 27 in the position of Figure 3 where all exhaust gases diverted by the valve are caused to flow through the manifold heating jacket before returning to the exhaust pi e. As the engine warms up, even on a cold ay, the hood temperatures as well as manifold metal temperatures increase with the result that the thermostat is warmed to a greater or less extent and its expansion rotates the valve into the position of Figure 4, or even to that of Figure 5 under extreme conditions. In Figure 4 it will be evident that a portion of the exhaust gases are available for heating the induction system while a portion are permitted to escape past the valve directly to the return p1pe 526. Figure 5 shows the valve 27 turned to its extreme cool position allowing and in fact forcing the bypassing of all the gas flow d rectly to the return pipe 26. This position is very desirable after the engine is warmed up in extremely warm climates and in fact under normal conditions if the carbureter side ofthe engine is so shielded as to cause high hood temperatures.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I therefore do not purpose limiting the patent granted .hereon otherwise than necessitate by the prior art. a r

I claim as my invention 1. In a device to divert products of combustion from the exhaust conduit of an automobile engine to heat the combustible mixrelationship to the'mixture conduit, said heatture, a heating chamber in heat exchanging 2. In a device to divert products of combustion from the exhaust conduit of an automobile engine to heat the combustible mixsensitive element to operate said valve, said thermosensitlve element being responsive to the temperature of the air contiguous to said engine, a valve in said exhaust conduit, a throttle valve in said mixture conduit, and means' inter-connecting said last mentioned valves for coincident operation.

3. In a device to divert products of combustion from the exhaust conduit of an automobile engine to heat the combustible mixture, a heating chamber in heat exchanging relationship to the mixture conduit, said heating chamber having an entrance and an exit, passages connecting said entrance and said exit to said exhaust conduit, a bypass passage between said entrance and exit passages, a valve in said bypass passage and a thermosensitive element to operate said valve, said .thermosensitive element being responsive to 4. In a device to divert products of combustion from the exhaust conduit of an automobile engine to heat the combustible mixture, a heating chamber in heat exchangin relationship to the mixture conduit, said heating chamber having an entrance and an exit, passages connecting said entrance and said exit to said exhaust conduit, a bypass passage between said entrance and exit assages, a valve in said bypass passage, a t ermosensitive element to o erate said valve, and means supporting sa1d thermosensitive element to operate said valve, and means supporting said thermosensitive element on sal en ine sothat it is heated by the joint effect 0 the radiation from'the engine, the conve ed heat from the radiator by the moving a1r and the conducted heat through the supports.

5. In a device to divert products of com- I bustion from the exhaustconduit of an automobile engine to heat the combustible mixture, a heating chamber in heat exchangin relationship to the mixture conduit, sai

heating chamber having an entrance and an exit, passagesconnecting said entrance and said exit to said exhaust conduit, a bypass passage between said entrance and exit passages, a valve in said bypass passage, and a thermosensitive element to operate said .valve, and means supporting said thermosensitive element on sa1d engine so that it is ring .ing fluid through said heating jacket, a byass valve for variably b passing said heatmg fluid away from said ieating jacket, and

thermostatic means for controlling said bypass valve, said thermostatic means being so mounted relative to the induction system that it is fully responsive to the surrounding air temperature and has a limited responsiveness to the heat conducted to the thermostat from the metal of the induction system.

7. A heat control for the induction system of an internal combustion engine, comprising a heating jacket associated with the induction system, means for diverting a heating fluid throu h said heating jacket, a throttle control of t e diversion of the su ply of heating fluid, a bypass valve for variribly bypassing said heating fluid away from sald heatin jacket, and thermostatic means for contro ling said bypass valve, said thermostatic means being so mounted relative to the induction system that it is adapted to secure a balance between the surrounding air temperature and to the heat conducted to the thermostat from the metal of the induction system.

8. A heat control for the induction system of an internal combustion engine, comprising a heating jacket associated with the induction system, means for diverting a heating fluid through said heating jacket, a bypass valve for variably bypassing said heating fluid away from said heatin jacket, and

- scribed my name at between the effect of the surrounding air temperature and metal of the induction iystem.

In testimony whereof have hereunto sub- Flint, Genesee County,

Michigan.

thermostatic means for controiling said by- 1 pass valve, and mounting means for said thermostatic means for limitin the conduc tivity of heat from said induction system to said thermostatic means whereby to obtain a predetermined balance between the effect of the surrounding air temperature and the heat stored up in the metal of the induction system.

heat control for the induction system? of an internal combustion engine, comprising a heating jacket associated with the inductlon system, means for diverting a heating fluld through said heating jacket, a throttle control of the diversion of the supply of heatmg fluid, a bypass valve for variably bypaming said heating fluid away from said heatin jacket, and thermostatic means for contro ing said bypassvalve, and mounting means for said thermostatic means for limiting the conductivity of heat from said induction system to saidthermostatic means whereby'to obtain a predetermined balance the heat stored up in the pal nae 

